Latched closed electric solenoid switch



Dec. 6, 1966 V, BEDGGQQD ETAL 3,290,631

LATCHED CLOSED ELECTRIC SOLENOID SWITCH Filed Aug. 13, 1963 5Sheets-Sheet 1 Dec. 6, 1966 V, BEDGGQOD ET AL 3,290,631

LAICHED CLOSED ELECTRIC SOLENOID swIICH 5 Sheets-Sheet 2 Filed Aug. 13,1963 Dec. 6, 1966 v BEDGGOOD ETAL 3,290,631

LATCHED CLOSED ELECTRIC SOLENOID SWITCH Filed Aug. 15, 1963 5Sheets-Sheet 5 lll-7&5

United States Patent O LATCHED CLOSED ELECTRIC SOLENOID SWITCH VictorBedggood, Maidens Green, Bracknell, and Eric Arthur Adam Fagan,Copthorne Common, Copthorne,

England, assiguors to Albright (Engineers) Limited,

Surbiton, England, a British company Filed Aug. 13, 196s, ser. No.301,s5s Claims. (Cl. 335-168) This invention relates to electricsolenoids. of the kind which include a single solenoid winding and theinvention is particularly but not exclusively applicable to electricswitches operable by means of such solenoids. Such solenoids having avariety of uses where it is required to impart movement to a particularcomponent as a result of energisation of the solenoid winding Iby meansof a direct or alternating electric current, the solenoid including anarmature member which may be mounted coaxially within the winding, whicharmature when moved as a result of energisation of the winding impartsthe necessary movement to the component. It is usual to provide a springeither associated with the armature or the component whereby thearmature and also the component will return to its initial position whenthe winding circuit is broken. Such solenoids have many uses and arecommonly employed in electric actuators or in the operation of electricswitches,

In known solenoid operated electric switches of this type, energisationof the solenoid Winding effects closure of the main contacts of theswitch and such contacts are held closed for as long as the winding isenergised. The contacts are spring-biassed to the open position andreturn to the open position under the action of the associated springupon de-energisation of the solenoid winding. Thus with such knownarrangements, in order to retain the contacts in the closed position,the current supply to the solenoid winding must necessarily bemaintained, resulting in a fairly heavy expenditure in energisingcurrent.

It is an object of the present invention to provide an electric solenoidincluding latching means operable each time the solenoid winding isenergised and means for restoring the armature of the solenoid each timethe winding is de-energised.

It is a further object of the present invention to provide an electricswitch of the solenoid operated type wherein means are provided forretaining the contacts in the closed position independently ofenergisation of the single solenoid winding, the current through whichis interrupted thereby decreasing current consumption to a very materialextent. K

Thus, according to one aspect of the present invention, there isprovided an electric solenoid of thesingle winding type having latchingmeans associated with the armature thereof and operable by movement ofthe armature to effect latching and unlatching thereof in response tomomentary energisation and subsequent momentary re-energisationrespectively of the solenoid winding, means for effectingde-energisation of the solenoid winding after each momentaryenergisation thereof and restoring means for returning the armature toits initial position without actuation of the latching means upon eachde-energisation of the-winding.

With such an arrangement, a component which has been moved as a resultof an initial momentary energisaice tion of the solenoid winding willtherefore remain in the new position until the winding is againenergised to actuate the latching means in an unlatching sense.

In a preferred embodiment of the invention, the circuit containing thesolenoid winding is automatically broken in response to actuation of thelatching means following energisation of the winding, thus effectingde-energisation thereof. The solenoid is provided with associatedchangeover contacts which are actuated to interrupt the circuit to thesolenoid winding in response to operation of the latching means, therebyeffecting de-energisation of the solenoid winding, at the same timepreparing a further circuit containing the solenoid winding, which whencompleted by operation of a switch, will connect the winding to asuitable current source to effect re-energisation thereof.

In a further embodiment of the invention, the latching means may bemanually operable by means of a plunger or push button attached to thearmature of the solenoid,

in the event of power failure in the energising circuit of the solenoidwinding.

According to a further aspect of the present invention there is providedan electric switch including a single solenoid winding, the maincontacts thereof being actuated to the closed position in response toenergisation of the solenoid winding, latching means for retaining themain contacts in the closed position and associated changeover contactslocated in the solenoid winding circuit and arranged to be actuatedsimultaneously with the operation of the latching means, such as tobreak the energising circuit to the solenoid Winding without opening ofthe main contacts of the switch.

The arrangement according to this aspect of the invention is such thatin response to further energisation of the solenoid winding via thechange-over contacts, the latching means is freed to allow the maincontacts to be restored to the open position under the action of anassociated spring.

The latching means is associated with the armature of the solenoid suchthat in response to successive energisation of the solenoid winding, thelatching means is actuated to close and open the main contacts of theswitch, and switch actuating means associated with the armatureoperating simultaneously with actuation of the latching means, effectopening and closing respectively of the circuit of the solenoid winding.

The electric switch-may also be manually operable through the medium ofa plunger or push button attached to the armature of the solenoid, suchthat in the event, for example, of a power failure in the energisingcircuit, the main contacts and associated latching means and auxiliarycontacts may be actuated by depression ofv the plunger or push button.Such a control for the switch would enable the switch to be used, forexample, for the control of a lift, where the plunger, as a result ofits coming into engagement with a fixed stop would actuate the maincontacts of the switch to their open position to break the mainelectrical circuit.

However, the electric switch according to the present invention isparticularly intended for operation from a remote point by means of oneor more push buttons located in the solenoid winding circuit andintended to control the energisation thereof. For example, a rstnormally-open push Ibutton is arranged, when actuated, to close theenergising circuit to the solenoid and effect energisation thereof viathe ON position of the auxiliary contacts, which are arranged within theswitch casing or externally thereof. Energisation of the solenoidwinding effects closure of the main contacts of the switch by movementof the armature; such movement also actuating the latching means andswitching the auxiliary contacts to the OFF position, thereby effectingde-energisation of the solenoid winding. The main contacts of the switchremainclosed being held in this position by the latching mechanism, andfurther operation of the irst push button will not elect the maincontacts of the switch or the solenoid winding in any way. A secondnormally-open push button is located in a line connecting the solenoidwinding to a source of current, and this line also includes the contactof the auxiliary contact in its OFF position. Thus, if the second pushbutton is actuated, the solenoid winding will again be energised toactuate the armature thereof and elfect release of the latchingmechanism, opening of the main contacts of the switch and therestoration of the change-over auxiliary contact to the ON position,thus again de-energising the solenoid winding, since the first pushbutton is in the normally-open position. The switch is thus in aposition to be operated as previvously described, by depression of thelirst push button, to close the main contacts, actuate the latchingmechanism and change-over the auxiliary contact thereby ensuring thatwhilst the main contacts are closed, no current is present in thesolenoid winding circuit.

The twin push button type of control is particularly useful where one-of the two push buttons must necessarily be placed in a comparativelyinaccessible position to prevent unauthorised operation. For example,the `first push button or push-on button as it will be hereinaftertermed, might be always accessible, whereas the second push button orpush-off button might be placed in a position in which it could not beoperated except with special authority, thus preventing the switch beingoperated in a circuit breaking sense once the switch has been closed.

The invention will now be described by way of example only withparticular reference to the acc-ompanying drawings and to theconstructional features of an electric switch according to theinvention, but it should be clearly understood that the invention is inno way limited to such an application, but, as previously indicated, haswider application to solenoids of the single winding type in general butit is considered that all the features of the solenoid will be clearlyapparent from the constructional features of an electric switch operatedby such a solenoid.

Thus, in the drawings:

FIGURE l is a sectional elevationy of the switch assernbly;

FIGURE 2 is a similar view to that of FIGURE 1, showing the solenoid andarmature construction of the switch assembly;

FIGURE 3 is a section taken along the line A-A of FIGURE 1 showing acam-operated change-over contact construction;

FIGURE 4 is a section taken along the line B-B of FIGURE l;

FIGURE 5 is a diagrammatic representation of the latching means, mainContact and change-over contacts showing the main contacts open andchange-over contacts in the ON position;

FIGURE 6 shows the main contacts closed and the change-over contacts inthe ON position;

FIGURE 7 shows the main contacts closed and mechanically latched and thechange-over contacts in the OFF position;

'FIGURE 8 shows the main contacts closed and the change-over contacts inthe OFF position;

FIGURE 9 is a perspective exploded View of the cam member for operationof the change-over contacts and i the cam surfaces of the latchingmeans; and

FIGURE 10 is a circuit diagram illustrating the manner in which t-hesolenoid winding is connected via the ON and OFF positions of thechange-over contacts and the push-on and push-off buttons respectively,to an energising source of current.

Referring to FIGS. 1 and 2, the switch assembly cornprises a U-shapedyoke 1 enclosing a solenoid winding 2 wound on a former 3, the yoke 1being secured to a back plate 4 by means of screws 5, as shown. Thearmature of the solenoid is shown at 6 and has secured thereto, by meansof screw 7, a manually-operable control knob 8. The armature 6 isslidably mounted in bearings 9 provided on la xed bearing support member10 located intermediate the armature 6 .and former 3. The armature 6 isprovided with an axial [bore 11 within which is located a sleeve 12provided with a shoulde-r 13 arranged to cooperate with a correspondingshoulder 14 on the armature 6 such that the sleeve 12 is carried forwardby the armature 6 when the knob 8 is depressed or the solenoid windingis energised. The end wall 15 of sleeve 12 is provided with a centralaperture 16 and a rod 17 is located wit-hin sleeve 12 and surrounded bya coil spring 18 held between the end wall 15 and a further sleevem'ember 19 slidable in sleeve 12. R-od 17 is provided at one end thereofwith an extension 20 `of reduced cross-sec tional area projectingthrough aperture 16 in end wall 15 of sleeve 12, and at the lother end,rod 17 has a further portion 21 of reduced cross sectional area passingthrough a contact bush moulding 22 on which is mounted the main movingcontact assembly 23 of the switch. The assembly 23 includes a contactsupport plate 24 provided on one surface thereof with a pair of movingcontacts 25, 26, the plate 24 being bolted to the rod 17 by a bolt 27.The bush moulding 22 is provided with a flange 28 Ibehind the shouldersof which is located a leaf spring 29 biassed into contact with plate 24.Washers 30 are located intermediate ange 28 and the end of rod 17 and afurther washer 31 is provided between bolt 27 and bush 22.

The fixed contacts of the main contact assembly are shown at 32, 33 inFIG. 1 and are arranged to mate with contacts 25, 26 respectively whenthe knob 8 is depressed or the solenoid winding 2 energised such as tomove contact assembly 23 forward as will be hereinafter described.Contacts 32, 33 are connected to terminals 34, 35 respectively and acoil spring 36 is provided between washer 31 and an end wall 37 of theswitch assembly.

The latching mechanism for retaining contacts 25, 32; 26, 33; in theclosed position and the cam-operated change-over contacts will now bedescribed. As shown in FIGS. l and 2, a plurality of projections 3-8extend from sleeve 19 and a-re each provided with a curved cammingsurface 39 arranged to co-operate with camming surfaces 40 formed on alatching member 41 (see also FIG. 9) slidably and rotatably mounted onrod 17 within housing 42 secured to back plate 4. The camming surfaces39, 40 are normally out of engagement as shown in FIGS. 1 and 2, or canbe in engagement dependent upon choice of length of spring 18, but arearranged Ito engage upon depression o'f knob 8 or energisation ofsolenoid winding 2 'to effect rotation of latching member 41 and cammingsurfaces -40 `secured thereto in a manner hereinafter described. A fixedstop member 43 provided with an oblique surface 44 is secured withinhousing 45 secured to back plate 4, as shown, and as will be described,stop member 43 is norm-ally arranged within a slot 46 formed in thelatching member 41 `to prevent rotation 4of latching member 41 which isprovided with cut away portions 47 for a purpose explained hereinafter.A coil spring 48 is located around tube 17 between a shoulder onlatching member 41 and washelr 30 and cam member 42 is provided withprojections 419 and cut-away portions 50 (FIG. accurate projections 49and cut-away portions 50 (FIG. 9), the former being arranged to engagewith a stud 51 formed on a rocker arm 52 when contacts 25, 32 and 25, 33are closed, and the latter being arranged to engage ril n? with the stud51 on the rocker arm 52 when the above contacts are in the open positionshown in FIGS. 1 and 2.

Referring to FIG. 3 a coil spring 53 is arranged between the rocker arm52 and a terminal stud S4 secured to a plate 55 provided on the frontsurface of back plate 4 (FIGS. 1 and 2). A link 56 of electricallyconducting material connects terminal stud 54 to the rocker arm 52 and acontact 57 is provided on the rocker arm 52 and arranged to rn-ate witha xed contact 58 provided on a terminal stud 59 mounted on the casing ofthe switch assembly. Contacts 57 and 58 are closed when the stud 51 isin engagement with the cut-away portion 50 of cam member 42 as shown inFIG. 3 and are opened when stud 51 is in engagement with raised portions49 of cam member 42. A further contact 60 is mounted on the end of aflexible arm 61 secured to rocker arm 52 and is arranged to mate with acontact 62 provided on a terminal Astud 63 mounted o the casing of theswitch assembly, contacts 60 and 62 being open when stud 51 is inengagement with a cut-away portion 50 of cam member 42 as shown in FIG.3 and closed when the stud 51 is in engagement with a raised portion 49of cam mem-ber 42. Thus contacts 57, 58 are closed when contacts 60, 62are open, and vice versa and contacts 57, 58; 60, 62 constitute thechange-over contacts of the auxiliary switching means of the switchassembly. Terminal leads 64, 65-connect studs 59, 63 to terminals 66, 67respectively and a further terminal point is shown at 68 in FIG. 4.

The operation of the main contacts in response to depression of knob 8or energisation or de-energisation of solenoid winding 2, the latchingof the main contacts in the closed position and the operation of thechange-over contacts to effect de-energisation of the solenoid windingafter the lat-ching Vmechanism has been actuated to retain the maincontacts in the closed position, will now be described with particularreference to FIGS. l, 2 and 3 and in conjunction with the diagrammaticrepresentations shown in FIGS. 5 to 8.

Assuming that the main contacts are open as shown in FIGS. l and 2, withthe solenoid winding de-energized, depression of the knob orenergi-sation of the solenoid winding will initially cause the armatureto move axially forward, carrying with it the sleeve 12, the sleeve 19secured thereto and the rod 17, allowing the contacts assembly 23 tomove forward to close the main contacts 25, 32; 26, 33. Since the fixedstop 43 is located within a slot 46 of the latching chamber 41, thelatter is held against rotation during this initial movement of thearmature 6 and contact assembly 23. The starting position is showndiagrammatically in FIG. 5 where the main contacts are shown Iin theopen position with the stop member 43 located within the slot 46 of thelatching member 41, and in this position, the change-over contacts arein the ON position necessary to effect energisation of the solenoidwinding 2, i.e. contacts 57, 58 are closed and contacts 60, `62 are openas shown in FIG. 3.

Following the closing of the main contacts, continued energisation ofthe solenoid winding or depression of knob y8, causes the armature 6 tocontinue its forward movement carrying with it the sleeve 19, thecamming surfaces 39 of sleeve 19 co-acting with camming projections 46of latching member 41 and pushing the latter axially until the stopmember 43 is disengaged from slot 46 in lat-ching member 41. The cammingmembers 38, 40 are now in a position to effect rotation of latchingmember 41 and associated cam member 42; the forward movement havingcompressed coil spring 48 and flexed leaf spring 29. At this point, thechange over contacts remain in the ON position with the main contactsheld closed by the pressure exerted by the forward movement of thearm-ature. This intermediate position is shown in FIG. 6. The cammingengagement of surfaces 39 and 40 rotates the latching mem-ber 41 through90, at which point the camming surfaces disengage and allow the latch- 5ing member 41 to be restored under the bias of spring 4S to the positionshown in FIG. 7 where the stop member 43 latches behind a cut awayportion 47 of latching member 41 thus inhibiting rotation thereof. Thisposition is shown in FIG. 7 where it will be seen that although the maincontacts 25, 32; 26, 33 remain closed, the changeover contacts have beenactuated to the OFF position to effect deenergisation of the solenoidwinding 2. This has been effected by the rotation of cam member 42bringing a raised portion 49 thereof into contact with stud 51 to effectactuation of rocker arm 52, thereby `moving contact 57 away from contact58 and closing contacts 6), 62. Since the change-over contacts arelocated in the solenoid winding circuit, the opening of contacts 57, 58will effect deenergisation of the solenoid winding 2, but since the stopmember 43 is located within the cutaway portion 47 of latching member41, the main contacts 25, 32; 26, 33, are held latched in the closedposition as shown in FIG. 7, without requiring that the solenoid remainenergised as in prior known arrangements.

Referring to FIG; 10, the change-over contacts are shown at A and B,with the moving contact thereof in the A or ON position, which isconnected to a terminal of a current source via the push-on button 69previously referred to. On depression of push-on button 69, the solenoidwinding 2 will be energised via the ON position (A) of ythe change-overcontacts and lead 70, to effect closure of the main contacts 23, 32, 33and operation of the latching mechanism as above described, such thatthe change-over contacts are changed to the OFF or B position, todisconnect the solenoid winding from the energising source of current.Further depression of push-on button 69 will not affect the switchcontacts in any manner. A further push button 71 (the push-off buttonhereinbefore -referred to) is located in the line connected to the aterminal of the current source. Thus, when the change-over contacts havebeen actuated to the OFF (B) position, the solenoid winding 2 may bereenergised by depression of push-off button 71 to open the maincontacts and restore the change-over contacts to the ON position as willbe hereinafter described.

Energisation of solenoid winding 2 or depression of knob 8 when thecontacts are in the position shown in FIG. 7, will cause the armature tomove forward again carrying with it sleeve 19 whose camming surfaces 39will engage camming surfaces 40 of latching member 41. Initially therotation of latching member 41 will be inhibited since the stop member43 is latched within the cut-away portions 47 of latching member 41 butthe continued forward movement of sleeve 19 will cause the lat-chingmember 41 to be pushed forward by the engagement of camming surfaces 39,K40, and eventually disengage the stop member 43 from the cut-awayportions 47 of latching member 41. This position is shown in FIG. 8 andthe latching member 41 will now be Ifree to rotate by engagement of therespective camming surfaces carrying with it the cam `member 42,bringing a cut away surface 50 thereof opposite the stud 51 (FIG. 3).The contacts 57, 58; `60, 62, will be restored to their initialpositions shown in FIG. 3 and the latching member 41 will be restored tothe position shown in FIG. 5 under the action of springs 29 and 48 wherethe stop member 43 once again engages in the slot 46 in the latchingmember 41 to inhibit rotation thereof. In this position of the switch,the main contacts have been opened and the change-over contacts restoredto the ON position (position A of FIG. l0), such that the solenoidwinding can be re-energised on depression of push-on button 69, ifnecessary, to once again close the main contacts of the switch.

Such a switch as has been hereinbefore described can be used as anisolation switch or alternatively as a limit switch in addition to itsother various applications and as previously explained can be energisedand released electrically or can be manually operated if the powersource fails.

Such a switch is suitable for D.C. or A.C. operation and in the case ofA.C. being used such a switch, due to the fact that the winding is onlyenergised for a short period, avoids the noise inherent in such switchesdue to pulsations of the energising current setting up chattering of thearmature. The switch cannot be released by means of subsequent actuationof the push-on button once the change-over contacts have been changed tothe OFF position and the main contacts mechanically latched and cannotbe energised ON by means of the push-off button. If necessary the switchmay be energised electrically and released manually -or vice versa orenergised and released electrically by means of one or more externalcontrolling circuits.

It will be appreciated that the invention is susceptible of considerablemodification and is not to be deemed limited to the particular featuresdescribed by way of example only,

For instance, although the features of an electric switch have beenparticularly described and the operation thereof from a remote point bymeans of the push-on and push-off buttons, it will be clear that thesolenoid when used to effect actuation of any component associated withthe armature thereof, can be similarly operated from a remote point bymeans of such buttons in conjuction with change-over contacts located inthe winding circuit.

What We claim is:

1. An electric solenoid of the single winding type having a movablearmature and latching means movable in response to movement of saidarmature to effect latching and unlatching thereof in response tomomentary energization and subsequent momentary re-energizationrespectively of the solenoid winding, means for effectingde-enerigization of the solenoid winding after each momentaryenergization thereof and restoring means for returning the armature toits initial position without actuation of the latching means upon eachde-energization of the winding, wherein the latching means includes astop member, fixedly mounted `within a casing of the solenoid, cammingmeans arranged to move with movement of the armature, a rotatablelatching member provided with camming surfaces anda slot within whichthe stop member is normally located to inhibit rotation of the latchingmember, which latter member is provided with a plurality of cut-awayportions, the arrangement being such that in response to energisation ofthe solenoid winding, the armature moves forward carrying forward thecamming means which coact with the camming surfaces of the latchingmember, initially pushing the latching member forward until the latteris disengaged from the stop member, following which rotation of thelatching member is effected by cooperation of the camming means andcamming surfaces of the latching member, until the stop member latcheswithin a cut-away portion of the latching member to inhibit rotationthereof.

2. An electric switch comprising a solenoid Winding and having anarmature to be .actuated in response to solenoid winding energization,contact means movable by said armature to a closing position, latchingmeans responsive to movement of said armature and comprising elements toeffect latching of said contact means in closing position and to effectsubsequent unlatching of said contact means, in response, respectively,to momentary energization and -subsequent momentary re-energization ofthe solenoid winding, de-energizing means actuated by said latchingmeans to effect de-energization of the solenoid winding after eachmomentary energization thereof, return means for returning the armatureto an initial position subsequent to de-energization, a cam memberrestrained to reciprocal movement movable by said armature, wherein thelatching means comprises a fixed stop member and a rotatable latchingmember connected to said contact means and provided with camming surfaceand having a slot within which the stop member is initially located toprevent rotation of said latching member,

said latchin-g member being provided with at least one cutaway portionhaving edges engageable by said cam member, whereby energization of thesolenoid winding actuates the armature to cause the cam member to engagethe camming 4surface of the latching member to initially translate thelatching member until the slot thereof is disengaged from the stopmember, followed by rotation of the latching member effected by coactionof said cam member and the camming surface of the latching member untilthe stop member engages within said cut-away portion of the latchingmember to preclude further rotation thereof, bias means for effectingpartial return translation of said latching member so that said stopmember has partial entry into said slot, said latching member being heldagainst full reverse translation by engagement of said latching memberin said cut-out portion whereby to latch said contact means in closingposition, said solenoid winding being then de-energized, and saidarmature being then in said initial position, whereby a subsequentenergization of said `solenoid winding actuates said armature to effectengagement of said cam member with said cam surface to initiallytranslate and then rotate said latching member, said latching member toeffect release of said latching member from said stop member and permitfull reverse translation of said latching member.

3. An electric switch as set forth in claim Z, said deenergizing meanscomprising a pair of switches, said actuating means comprising a camconnected to said latching member, whereby when one switch is open theother is closed, responsive to rotation of said latching member, saidswitches being connected to effect respective current paths to saidsolenoid winding so that energization of said solenoid winding can beinitially effected via one switch whence rotation of said latch memberopens said one switch to de-energize said `solenoid winding and closesthe other switch to condition said solenoid winding for reenergizationvia said other switch.

4. An electric switch comprising a solenoid winding, main contactsactuatable in response to energization of said solenoid winding to aclosing or opening position, actuatable latching means operativelyconnected to said main contacts and comprising members for retaining aclosing position of said main contacts upon energization of saidsolenoid winding, a pair of switches each connected in series with saidsolenoid winding, means connected to said latching means for actuatingsaid switches by actuation of said latching means to either opening orclosing position of said main contacts whereby one switch is closed andthe other open at either of said positions, so that said solenoidwinding may be initially energized through one of said switches by saidlatching means when said latching means is in initially non-latchingposition and said solenoid winding is de-energized by opening of saidswitch by said latching means when said latching means is subsequentlyin latching position, the other of said switches being then closed tocondition said solenoid winding for re-energization.

5. A solenoid switch comprising a solenoid winding, an armature, maincontact means, means for moving said main contact means into a closingposition by said armature upon energization of said solenoid winding, alatch member reciprocally movable by said armature when moving said maincontact means is moved to .a closing position, latch means coacting withsaid latch member to latch it in a predetermined position to which ithas been reciprocated, said latch member being connected to said maincontact means to hold said main contact means in lclosing condition atthat time, said latching member being rotatively mounted, and means foreffecting rotation of said latching member substantially at the timesaid main contact means have been moved to closing position, means forreleasing said latching member for reverse reciprocal movement to permitopening of said main contact means and for effecting rotation of saidlatching member substantially at that time, and a pair of switchesoperable by said latching member and in response to rotation thereof,and being connected to said solenoid Winding, one switch being closed tocondition said solenoid for energization when said main IContact meansis in open position, and the other switch being closed to condition saidsolenoid Winding for energization when said main contact means are inclosing position, and means whereby said switches are alternativelyoperated to open and closed positions by sequential rotational movementof said latching member.

References Cited by the Examiner UNITED STATES PATENTS Durdin 200-111Wescott 200-111 Wilms et al. 200-104 X Bordelon 20G-87 X Zipper 317-192X Keirans 20D- lll X Whinery 200-137 X BERNARD A. GLHEANY, PrimaryExaminer.

T. D. MACBLAIN, Assistant Examiner.

UNITED STATES PATENT OEEICE CERTIFICATE OF CORRECTION Patent No 3 ,V290,631 December 6, 1966 Victor Bedggood et al.

r appears in the above numbered pat- It is herebj)T certified that errotters Patent should read as ent requiring correction and that the saidLe corrected below.

In the heading to the printed specification, line 5, for "assignors toAlbright (Engineers) Limited, read assignors of one-half to Albright(Engineers) Limited,

Signed and sealed this 24th day of October 1967.

(SEAL) Attest:

EDWARD J BRENNER Commissioner of Patents Edward M. Fletcher, Jr.

Attesting Officer

1. AN ELECTRIC SOLENOID OF THE SINGLE WINDING TYPE HAVING A MOVABLEARMATURE AND LATCHING MEANS MOVABLE IN RESPONSE TO MOVEMENT OF SAIDARMATURE TO EFFECT LATCHING AND UNLATCHING THEREOF IN RESPONSE TOMOMENTARY ENERGIZATION AND SUBSEQUENT MOMENTARY RE-ENERGIZATIONRESPECTIVELY OF THE SOLENOID WINDING, MEANS FOR EFFECTINGDE-ENERGIZATION OF THE SOLENOID WINDING AFTER EACH MOMENTARYENERGIZATION THEREOF AND RESTORING MEANS FOR RETURNING THE ARMATURE TOITS INITIAL POAITION WITHOUT ACTUATION OF THE LATCHING MEANS UPON EACHDE-ENERGIZATION OF THE WINDING, WHEREIN THE LATCHING MEANS INCLUDES ASTOP MEMBER, FIXEDLY MOUNTED WITHIN A CASING OF THE SOLENOID, CAMMINGMEANS ARRANGED TO MOVE WITH MOVEMENT OF THE ARMATURE, A ROTATABLELATCHING MEMBER PROVIDED WITH CAMMING SURFACES AND A SLOT WITHIN WHICHTHE STOP MEMBER IS NORMALLY LOCATED TO INHIBIT ROTATION OF THE LATCHINGMEMBER, WHICH LATTER MEMBER IS PROVIDED WITH A PLURALITY OF CUR-AWAYPORTIONS, THE ARRANGEMENT BEING SUCH THAT IN RESPONSE TO ENERGISATION OFTHE SOLENOID WINDING, THE ARMATURE MOVES FORWARD CARRING FORWARD THECAMMING MEANS WHICH COACT WITH THE CAMMING SURFACES OF THE LATCHINGMEMBER, INITIALLY PUSHING THE LATCHING MEMBER FORWARD UNTIL THE LATTERIS DISENGAGED FROM THE STOP MEMBER, FOLLOWING WHICH ROTATION OF THELATCHING MEMBER IS EFFECTED BY COOPERATION OF THE CAMMING MEANS ANDCAMMING SURFACES OF THE LATCHING MEMBER, UNTIL THE STOP MEMBER LATCHESWITHIN A CUT-AWAY PORTION OF THE LATCHING MEMBER TO INHIBIT ROTATIONTHEREOF.